I have some generic server rack layout questions in regards to component placement. I see some racks with the patch panel at top and some with it at the bottom, i see some with the controller up top and some with it at the bottom.
So my question is, are there any rules or best practice for component rack layout? heaviest at bottom lightest at top? Cables at the top or bottom seems better than in the middle, in regards to getting easy access to them (I always seem to have to add or remove them for some reason)
The only basic requirement is heavy things go near the bottom, this helps prevent the rack from tipping over when you slide them out on the rails for service. So within reason, big UPS at the bottom, big storage at the bottom, light single RU compute servers higher.
Also lifting heavy things higher is NO FUN, I’ve had to rack up heavy things like 30+ pound video tape recorders, even with slide rails, it is no fun and semi dangerous.
The only exception I might suggest is that sometimes heavy things go where you can slide them off of a cart and into their rails. This prevents almost all of the lifting problems. My two “big” storage units and mounted this way. I really need to get a hydraulic lift cart to get height adjustability into the mix. That said, I still won’t mount these heavy things above the mid point, just too much risk of a tip over, even if the racks are bolted down.
A full on datacenter will be different, and probably have switching in several places within the rack, Serve the Home has shown a couple really big datacenters and they put switching where it’s needed, when it’s needed to support the number of connections needed for the design. Short DAC cables are probably better than long DAC cables unless they are optical.
For me, switches and patching go where it seems right, might be middle, might be top. Right now I have my switching in the top like traditional “top of rack”, did the same for my lab because things just fit there better with the layout I was forced into. I was considering putting it in the middle, but the depth just didn’t fit. I’ll probably have some picture of my new lab rack soon.
AS Greg already stated: heavy stuff at the bottom and the rest is more or less a matter of personal preference. Having patch panels on the top might be more convenient for patching as you won’t kneel down to do patching.
However, maybe more important about the position of the patch panels is a good cable management. You want to avoid loose hanging cables and a mess of interweaved cables.
I’ll also mention that different length hook and loop cable wraps should be used. I do not recommend nylon tie wraps unless you are certain things are “permanent”. The hook and loop allow you to add, remove, reposition, etc., the cables. You’ll want different lengths for different bundles and for attaching to different points on the rack. You can also use them for stuff like AC to DC power supplies to hold them to the rack, and assorted other things. I’ve been using these https://www.cablematters.com/pc-1698-164-100-pack-assorted-reusable-hook-and-loop-cable-ties-468-inches.aspx and also the 8 inch pack for things in lab and production. I got mine from Amazon.
Planning and labeling are also important.
For example, in my home lab, I have the switch on the bottom, and the patch panel is above. Easier to route cables and could access them without removing big items.
Having a consistent naming scheme and labeling (almost) every item/cable. I can’t count how many times I said: I will remember that the top port is eth0…and half an hour later…
Also, I second the Velcro cable ties. Things change, and there is nothing more annoying than carefully removing zip ties.